Study of the aromatic oxidation markers of Tempranillo long aged wines

New Plant Breeding Techniques (NPBTs) have the potential to revolutionize the genetic improvement of grapevine. However, the practical application of these techniques is limited by several challenges, such as the difficulty in generating embryogenic calluses, maintaining their competence during in vitro cultivation, and regenerating plants without defects. To overcome these challenges, we conducted a study to test the effect of two treatments on callus cultures derived from different grapevine varieties, with and without embryogenic competence. The tested substances were Silver Thiosulphate (STS) an ethylene inhibitor, and Salicylic Acid (SA), an elicitor with different effects depending on the concentration of use beyond the ethylene inhibitor activity.

Context and purpose of the study – Viticulture faces significant challenges due to climate change, with increased frequency of extreme weather events impacting grapevine growth, grape quality, and wine production.

In the Cognac region in France, Ugni blanc is the most planted grape variety (98% of the 80 500 ha). This vine region is in expansion due to the success of the associated well-known brandy and the need of high grape yield to guarrantee the production of base wine for distillation. About 2 to 3000 ha are newly planted each year and rootstocks are one powerfull tool for vineyard adaptation to soil or climate change. As rootstocks ensure water and mineral nutrient supplies to the scion, it is important to better understand their effect on berry compostionnal parameters such as sugars and nitrogen compounds, which are the main precursors for fermentary aroma metabolites, the latter being quality markers for Cognac after distillation.

The Precision Viticulture (PV) is defined “as a management system that is information and technology based, is site specific and uses one or more of the following sources of data: soils, vigour, nutrients, pests, moisture, and yield among others, for optimum profitability, sustainability, and protection of the environment” (OIV, 2018, in process). The elements mentioned in the definition are an important part of the terroir components. The terroir is a tool In Viticulture, it is the analysis and study unit, and the variability of a certain situation can be due to any difference in every element or property of each factor that constitutes it, including the management.The soil and its management are those that bring the most variability to terroir.

For coopers, seasoning and toasting are considered crucial steps in barrel making during which the oak wood develops specific organoleptic properties. Seasoning, carried out in the open air, allows reducing the moisture content of the staves to between 14 and 18% (compared to 70 to 90% after splitting) while modulating the intrinsic composition of the oak wood. Toasting consists of applying different degrees of heat to a barrel for a specific period of time. As the temperature increases, oak wood produces a wide range of chemical compounds through thermal degradation of its intrinsic composition.